Frogs Call at a Higher Pitch in Traffic Noise
Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call […]
Rumble vocalizations mediate interpartner distance in African elephants, Loxodonta africana
The ability to utilize contact calls to facilitate reunions with social partners has been documented in a number of species showing a fission/fusion social organization. Field observations and playback experiments suggest that African elephants use low-frequency rumble vocalizations to reunite with their herd members following periods of fission. Using a digital audio and GPS recording […]
Predator-associated vocalizations in North American red squirrels, Tamiasciurus hudsonicus: are alarm calls predator specific?
North American red squirrels are a small-bodied, solitary territorial species that faces a diversity of predators. One report suggested that red squirrels produce two distinct vocalizations to aerial and ground predators: a tonal [`]seet’ and a broadband [`]bark’, respectively. This categorical mapping between alarm call variants and predator classes suggested that red squirrels might manifest […]
Acoustic Interaction in Animal Groups: Signaling in Noisy and Social Contexts
It has long been known that individuals of many species vocally communicate with one another in noisy environments and in rich contexts of social interaction. It has recently become clear that researchers interested in understanding acoustic communication in animal groups must study vocal signaling in these noisy and socially complex settings. Furthermore, recent methodological advances […]
Indicators of age, body size and sex in goat kid calls revealed using the source-filter theory
The source-filter theory is an important framework recently applied to the study of animal vocalisations, which links the mode of vocal production to call parameters. Vocalisations can be good indicators of a sender’s characteristics, such as identity, body size, age, and even hormonal status and affective states. For these reasons, applied vocal communication research would […]
Giant Pandas Attend to Androgen-Related Variation in Male Bleats
Although androgen-dependant traits are predicted to signal overall male quality, no study has examined the response of a nonhuman animal to variation in a known acoustic cue to male androgen levels (steroid hormones that are key drivers of male sexual behaviour). Here, we use a single-speaker approach to present male and female giant pandas with […]
Female koalas prefer bellows in which lower formants indicate larger males
Despite an extensive literature on the role of acoustic cues in mate choice little is known about the specific vocal traits that female mammals prefer. We used resynthesis techniques and playback experiments to examine the behavioural responses of oestrous female koalas, Phascolarctos cinereus, to male bellows in which a specific acoustic cue to body size, […]
The effect of habitat acoustics on common marmoset vocal signal transmission
Noisy acoustic environments present several challenges for the evolution of acoustic communication systems. Among the most significant is the need to limit degradation of spectro-temporal signal structure in order to maintain communicative efficacy. This can be achieved by selecting for several potentially complementary processes. Selection can act on behavioral mechanisms permitting signalers to control the […]
An experimental study of duet integration in the happy wren, Pheugopedius felix
Pairs of duetting birds can sing coordinated duets with such precision that they are often mistaken for a single individual, yet little is known about how this impressive temporal synchronization is achieved. We experimentally examined duet coordination in male happy wrens, held briefly in captivity, by playing song phrases from their partner at different distances […]
Acoustic analysis of cattle (Bos taurus) mother–offspring contact calls from a source–filter theory perspective
Cattle vocalisations have been proposed as potential indicators of animal welfare. However, very few studies have investigated the acoustic structure and information encoded in these vocalisations using advanced analysis techniques. Vocalisations play key roles in a wide range of communication contexts; e.g. for individual recognition and to help coordinate social behaviours. Two factors have greatly […]